Apparatus for preparing lined piping flanged pipe joints



y 1, 1966 H. H. AL-BRO 3,253,449

APPARATUS FOR PREPARING LINED PIPING FLANGED PIPE JOINTS Original FiledOct. 5, 1961 3 Sheets-Sheet 1 Fig.l Fig.2

INVENTOR Henry H. Al bro ATTORNEY H. H. ALBRO 3,253,449

APPARATUS FOR PREPARING LINED PIPING FLANGED PIPE JOINTS May 31, 1966 3Sheets-Sheet 2 55 Original Filed Oct. 5, 1961 INVENTOR Henry H. Al bro50 xii KWMK ATTORNEY y [966 H. H. ALBRO 3,253,449

APPARATUS FOR PREPARING LINED PIPING FLANGED PIPE JOINTS Original FiledOct. 5, 1961 3 Sheets-Sheet 5 INVENTOR Henry H. Albro BY U MMMX ATTORNEYUnited States Patent This application is a division of my copendingapplication, Serial No. 146,066, filed October 5, 1961.

This invention relates to unobstructed, leak-proof, lined pipingsystems, and more particularly to an apparatus for preparing flangedconnections of lined piping.

In the handling of flowable corrosive materials, it is customary toemploy a metallic pipe lined with a corrosion-resistant plastic or thelike and to connect such pipe to an adjacent pipe or to a lined pipefitting by means of flanged couplings having a sealing means interposedtherebetween.

When the coupling is to employ lined pipes flared at their ends and withsealing means such as suitably tapered plastic stub ends intended to beinserted therein for seal- 7 ing purposes, splitting of the metallicpipe, damage to the pipe lining and separation of the lining from thepipe may occur during the flaring operation, unless careful precautionsare taken. This flaring operation, which preferably should be capable ofbeing conducted under field conditions, presents a diificult problem dueto the inherent nature of the plastic lining and to its tendency tobreak its bond with the pipe, whether that bond is of a mechanical or acemented nature. It is a purpose of this invention to overcome thisproblem in'a simple and inexpensive manner and an object of theinvention is to provide an improved apparatus for flaring the ends ofplastic lined metallic pipes.

Other objects and advantages will become more apparent as thedescription proceeds and when considered in conjunction with theaccompanying drawing in which:

FIG. 1 is a front elevation view of a stub end pipe fitting adapted forbonding to the flared end of the lined pipe.

FIG. 2 is a sectional view taken on line 2-2 of FIG. 1.

FIG. 3 is a longitudinal sectional view through the juxtaposed ends of apair of pipes prepared in accordance with the invention and prior tofastening the same into the final flanged connection therebetween.

FIG. 4 is a perspective view of the flaring apparatus in assembledposition preparatory to its flaring movement, and with portions of theapparatus shown in section.

FIG. 5 is an end view of the two-part tapered collar taken fromthesmaller end and showing one of the serrated teeth in each part.

FIG. 6 is a side elevation view of the flaring plug inserted in the pipeto be flared and shown at the beginning of the flaring operation.

FIG. 7 is a side elevation of the flaring plug showing the position ofthe same within the pipe at the conclusion of the flaring operation.

FIG. 8 is a view, partly in section, and partly in side elevation,showing the flaring plug in position within the pipe during theattachment of the metallic flange and the reducing of the restoringforce in the flared plastic lining, and

FIG. 9 is a longitudinal sectional view of the flared pipe end and thestub end fitting preparatory to insertion and bonding of the stub endwithin the pipe.

In accordance with the invention, a simple and inexpensive apparatus forpreparing flanged pipe joints for lined pipes, and involving the flaringof the ends of such pipe without damage to the pipe or to the liningthereof, is

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made available for use in the construction of unobstructed, leak-proof,lined piping systems.

Referring first to FIGS. 1 and 2, a plastic stub and fitting of the typeshown in the copending application of Carl B. McLaughlin, Serial No.143,105, filed October 5, 1961 (now abandoned), and assigned to theassignee of the present invention, is employed in the pipe joint. Thisfitting may be formed of any of several known plastic materials, forexample, unplasticized polyvinyl chloride, chlorinated polyethers, orthe like, and may be shaped into the prescribed form by conventionalmolding or machining operations. The run portion 10 of the fitting(shown herein with an exaggerated wall thickness) has a cylindricalinner surface 11, with a diameter preferably equal to the normal innerdiameter of the pipe lining with which the fitting is to be employed,and has a tapered outer surface 12 gradually diminishing along itslength from a maximum adjacent its flanged portion to a minimum at thedistal end of the run portion. The truncated conical surface 12 isadapted to be bonded to the flared lining of the pipe, which itself isadhered to that pipe. The precise bonding procedure may vary accordingto the nature of the plastic material and may include cementing, surfaceheating, or other conventional bonding procedures. As an example, acemented bonding may be effected, as by means of a solvent cementcovering the respective surfaces as shown in FIG. 9, and followingcertain steps of preparation in accordance with the invention, as willlater appear.

Extending generally normal to the axis of the run portion of the stubend and located at the end thereof, and integral therewith, is a flangeportion 13, the back surface 14 of which is flat. The front surface 15of the fiange preferably, but not necessarily, is outwardly tapered asbest seen in FIG. 2, and in general a taper of about 1 is satisfactory.In addition, the surface 15 preferably, but not necessarily, is providedwith concentric grooves, for example, about 0.015 inch deep and with auniform pitch of about 0.03 inch. As seen in FIG. 3, the above describedfitting is inserted, either at the factory or in the field, into theflared end of a lined pipe. This pipe may comprise an initially roundstructure, as shown in FIG. 6, having an outer tubular steel portion 16and with'an inner tubular plastic portion 17 therein and suitablyadhered thereto. At its flared extremity the pipe is engaged by anannular back-up metallic flange 18 which may be suitably tapered at itscenter to embrace the flared end of the pipe. The metallic flange iswelded as at 19 to the outer surface of the metallic pipe. This back-upflange provides a flat abutment surface 20 against which the surface 14of the fitting contacts at the time of assembling the parts, the back offlange 18 having a greater diameter than the stub end flange, andincluding holes 21 through which bolts (not shown) may be passed to formthe completed pipe joint.

As will be understood, the inner diameter of the plastic lining 17 ofthe pipe to the right of the peripheral line 22 (FIG. 3) is preferablyequal to the inner diameter of the run portion of the stub end fitting.When a cementing bonding procedure is employed and as illustratedherein, any excess bonding material squeezed from its space between thesurface 12 of the stub end and the flared inner surface of the pipelining serves to fill in the periphery of the space immediately to theright of the end of the emplaced pipe fitting, as shown at 23, andwithout forming an obstruction to normal flow through the pipe. Atypical lined piping system employing stub end fittings as abovedescribed may include two pipes similarly equipped with a stub endfitting and arranged in juxtaposed relation, similar portions of thesecond pipe being designated by characters with the suffix A. It will befurther understood that the invention is applica 'ble to pipe jointscomprising a lined pipe connected to a lined pipe fitting, such as alined T, and is not limited, therefore, to use with two lined pipes, asillustrated in FIG. 3. Although not generally required, a separate flatannular sealing gasket 30 of conventional material may be employed inthe combination as shown in FIG. 3, if desired by the user. Having thusdescribed the nature of the pipe joint and parts whose preparation thepresent invention is intended to assist, reference now is made to FIG. 4showing the improved flaring apparatus. At the outset, it may be notedthat the plastic lining 17 Within the metallic pipe 16 is normallyadhered thereto by various types of bonds, such as cemented bonds,mechanical bonds or the like, and that the thickness of, and modulus ofresilience of, that layer of plastic is such as to establish anappreciable restoring force therein whenever the material is subjectedto the flaring stresses and compression incident thereto. Withoutprovision for reducing that restoring force, the plastic lining wouldtend to break its bond with the flared end of the metallic pipe,interfere with the proper insertion of the stub and fitting, and perhapsendanger the integrity of the sealed joint when corrosive materials areto be handled. The flaring apparatus and the method with which it isemployed take this characteristic of the pipe lining into account aswill now become apparent to those skilled in the art.

In its preferred form, the flaring apparatus or fixture is portable, maybe handled by a single operator, and includes at one end a readilyseparable yoke having complementary identical sections 40 and 41. Eachsection is provided with an opening extending parallel to the axis ofthe pipe to be flared and receiving therethrough a threaded bolt 42 and43, respectively, adapted to withstand the tension imposed during theflaring, and being held by suitable nuts. By means of removable capscrews in each yoke section engaging with the other yoke section, onesuch screw being shown at 44, these sections may be readily assembledinto a unitary yoke member. Each section of the yoke is provided with atapered arcuate central aperture complementary to the tapered apertureof the other yoke section, the larger diameters of which are located onthe side from which the tension rods extend, and with these taperedapertures having diameters substantially greater than the diameter ofthe pipe to be flared. Insertable within these tapered apertures in themanner shown in FIG. 4, is a segmental collar or retainer having taperedouter surfaces corresponding to the taper of the apertures and with aseries of axially spaced serrations or teeth on the inner peripherywhich engages the pipe. These teeth extend circumferentially and have asaw tooth edge providing biting contact with the pipe in the directionof pull of the tension rods. As seen in FIG. the collar may convenientlycomprise two complementary portions 45 and 46, respectively, having attheir ends 47 and 48 of smaller outer diameter, semi-circular teeth 49and 50, and with similar teeth as shown in FIG. 4 being disposedlengthwise of these portions.

Attached at the distal ends of the tension rods is a massive abutmentmember 51 extending transversely of the axis of the collar and spacedfrom that collar a sufficient distance to provide working space for theelements now to be described. A metallic flaring plug having a forwardlyprojecting tubular pilot or guide end 52, with an outer diameter notlarger than, and preferably equal to, the inner diameter of the lining17, includes a tubular body portion 53 of gradually increasing outerdiameter extending from the pilot end to a cylindrical disc base oranvil portion 54. The diameter of this base, the forward flat surface 57of which lies in a plane normal to the axis of the pipe, is generallylarge enough to provide ready clamping to the flange 18 and small enoughto afford free movement between the spaced tension rods, while thethickness of the base is sufficient to withstand the flaring stressimposed thereon. At suitably spaced locations circumferentially of thebase, a series of threaded holes are provided and within whichretracting bolts 55 and 56 are threadedly engaged.

A conventional hydraulic jack having a cylinder 60 with an actuatingfluid conduit 61 connected thereto is provided for use with the flaringplug. The jack,-0r equivalent extensible pressure applying member shouldbe of adequate size and capacity to insure an uninterrupted flaring ofthe metallic pipe after such flaring is initiated. When arranged forflaring usage, the axis of the cylinder and of the piston 62 projectingtherefrom coincide with the axis of the flaring plug and of the pipe tobe flared, the base of the cylinder meanwhile resting in contact withthe abutment 51.

With the foregoing description of the improved flaring apparatus inmind, the following description of the method of the invention and ofthe advantage to be secured through usage of that apparatus, will nowindicate the utility of the same for preparing pipe joints employing theearlier described stub end fitting. With a metallic back-up flange 18arranged in loose enveloping relation to the lined pipe and with thetapered central aperture 63 thereof arranged with its larger diameterfacing the end of the pipe, the pilot and body portion of the flaringplug are then coated with a suitable silicone lubricant. The segmentalcollar portions 45 and 46 are engaged with the metallic pipe 16 at asuitable distance from the pipe end, a distance of 3-4 inches beinggenerally suitable, and with these collar portions snugly engaging inthe tapered recesses of the assembled yoke. The pilot portion of theplug is then carefully aligned in the lined pipe and the jack isinserted in position and actuated to bring its piston into contact withthe base 54 of the plug. At this time the lining 17 and the plug occupythe relative positions seen in FIG. 6 and no restoring force has beenbuilt up in that lining. The operator then causes the piston of the jackto move forward slowly with an uninterrupted movement until the surface57 of the plug contacts the end of the metallic pipe, as shown in FIG.7, thus effecting the desired flare at the end of the pipe and placingthe lining 17 at the flared end of the pipe under substantialcompression loading, as related to any given increment of the liningconfined radially of the pipe between the plug and the metallic pipe 15.In addition, as will be understood, the diameters of the lining and ofthe metallic pipe at the flared regions thereof have been increased andthe lining considered as a whole has acquired a substantial stress intension which may conveniently be termed its restoring force. At thistime the restoring force in the stressed lining reaches its maximumvalue and if the plug were immediately removed, would be sutficient tobreak the bond between that lining and the flared end of the metallicpipe. However, in accordance with the invention, the jack is merelyactuated at this time in a rearward direction, relieving tension in rods42 and 43 and permitting the fixture to be suitably disassembled andremoved, while leaving the plug in position within the flared pipe.Promptly thereafter the operator moves the metallic flange 18 to theflared end of the pipe at which time the tapered central aperture 63 ofthe flange moves snugly into circumferential contact with the flaredouter surface of the metallic pipe 16, and with the flat surface 20 ofthat flange extending at least to the end of the flared pipe. Suitableclamps as shown at 64 and 65 are then engaged with the back-up flangeand the base 54 of the flaring plug to hold the same in rigidcooperation during the immediately following, and significant, weldingstep. This welding step preferably is conducted with a conventionalwelding apparatus using high-nickel content rods such as Eutetic Alloys680 or one of the type 300 stainless steel electrodes which have theadvantage of requiring relatively low amperage to make a good tack weldand which weld can be water quenched without cracking In carrying outthe welding step, the operator first tack welds the flange 13, as at oneof the welds 19, to the metallic pipe and immediately quenches the weldwith water. During the application of the welding heat the compressedplastic lining is heated and undergoes a change of molecular structurewhich relieves the same of at least a portion of its restoring force, ormemory-effect, the magnitude of this reduction in the restoring forcebeing suflicient to avoid later breaking of the bond between thatplastic lining and the flared end of the metallic pipe. The immediatecooling of the weld, moreover, prevents degradation of the plastic,which normally is of a-thermoplastic nature. The second of the tackwelds 19 is then made in similar manner at a location generallydiametrical from the first weld, after which the clamps may be removedand a series of intermediate tack welds, about six spaced equidistantly,are then made in similar manner. Depending upon the plastic materialsinvolved, and upon the rated loadings expected of the pipe joint, thedescribed tack welding may sufiice, or may be continued, with aquenching following each increment of additional Weld until a completeweld extending circumferentially of the metallic pipe, if formed.

Following the described welding step and its concomitant treatment ofthe plastic lining, the flaring plug retracting bolts 55 and 56 are thencarefully operated to withdraw the flaring plug axially from theflange-equipped flared pipe end leaving the same in readiness formounting the stub end therein, as seen in FIG. 9, and Without stressingthe flared lining of the pipe, which lining remains bonded to that pipe.After the flaring plug is thus removed, the mating surfaces of the linedpipe and of the stub end may be wiped clean with a cloth moistened inmethyl ethyl ketone in order to remove extraneous material, such as thesilicone lubricant, after which those surfaces may be coated with thesolvent cement 100, if a cemented bond is to be made. The stub end shownin FIG. 9 is then moved into the flared end of the pipe, given arotation to insure even distribution of the cement, and thereafter aprotective block (not shown) may be placed over the outer edge of theemplaced stub end and clamped to the flange 18 until the bond ishardened, a period of 15 minutes usually being suflicient for ahardening of that bond. As will be also noted, when the stub end isproperly inserted in the pipe, the surface 14 of its flange abutsagainst the surface 20 of the metallic flange as best seen in FIG. 3,thus assuring the maintenance of the integrity of the bond with the pipewhen the thus equipped pipe is incorporated into the piping system, asmore fully set forth in the afore-mentioned McLaughlin application. Thedescribed apparatus is especially well adapted for flaring metallicpipes which tend to split under conditions of metal work-hardening. Withthe apparatus in place no interruption of the forward-flaring motion ofthe flaring plug is necessary, and when the jack 60 begins to apply itsflaring pressure, it may continue to apply the same without pause untilthe completed flare is accomplished, thus minimizing the danger ofsplitting of the metallic plpe.

While I have shown and described particular method and apparatusembodiments of the invention, I do not desire the invention to belimited to the particular embodiments disclosed, but rather I intend bythe appended claims to cover all modifications within the true spiritand scope of the invention.

What is claimed is:

1. Apparatus for flaring the end of a plastic lined metallic pipe withthe lining bonded thereto and comprising in combination, a demountableassembly adapted for temporary support upon the end of the pipe duringthe flaring of the pipe and including a yoke having a central truncatedconically shaped aperture for surrounding said pipe in spaced relationthereto and with its larger diameter nearor that end of said pipe whichis to receive the flare, a segmental pipe-engaging-collar having aplurality of separate arcuate sections, each section having a taperedouter surface engageable in mating relation with the aperture in saidyoke and having a serrated inner surface engageable with a portion ofthe periphery of said pipe adjacent the end of the pipe which serves asa support for said assembly, an abutment member extending transverselyof said pipe and located sufl'iciently far from the end thereof toprovide an open working space therebetween, means rigidly and adjustablyconnecting said abutment to said yoke and completing the detachableassembly supported by said pipe; a flaring plug having a base portion, acylindrical guide portion with anouter diameter no greater than theinner diameter of the uncompressed lining of said pipe, and a taperedflaring portion connecting said base and guide portions; and anextensible pressure-applying member separate from said plug and saidabutment and located in said open space and adapted to push upon each ofsaid abutment and said base portion of said plug during the flaringoperation, said extensible member being adapted when moved in anextending direction to force said plug into said pipe and to imposetension upon said connecting means and when moved in a contractingdirection to relieve said tension whereby said yoke, collar, andabutment may be removed from their temporary support upon said pipe,thus to leave said plug in place within said pipe in order to maintaincompression upon the plastic lining in the flared end of said pipe.

2. Apparauts as defined in claim 1 wherein said yoke comprises a pair ofcomplementary members detachably secured to each other, and saidconnecting means includes a pair of tension rods, one end of each rodbeing connected to each of the respective members of the yoke and theother end thereof being connected to said abutment member.

3. Apparatus as defined in claim 1 wherein said base portion of saidflaring plug includes a forwardly disposed flat surface normal to theaxis of said plug and laterally extending from the rearmost portion ofsaid tapered portion of said plug, and adapted to contact the end ofsaid pipe when said plug is fully inserted therein.

4. Apparatus as defined in claim 1 wherein said base portion of saidflaring plug includes means mounting a retracting means for withdrawingsaid plug from the flared end of said pipe.

References Cited by the Examiner UNITED STATES PATENTS 2,209,739 7/1940Meyer 72-370 2,535,470 12/1950 Welshman 72-370 3,086,575 4/ 1963 Knowal'7237O CHARLES W. LANHAM, Primary Examiner.

RICHARD J. HERBST, Examiner.

1. APPARATUS FOR FLARING THE END OF A PLASTIC LINED METALLIC PIPE WITHTHE LINING BONDED THERETO AND COMPRISING IN COMBINATION, A DEMOUNTABLEASSEMBLY ADAPTED FOR TEMPORARY SUPPORT UPON THE END OF THE PIPE DURINGTHE FLARING OF THE PIPE AND INCLUDING A YOKE HAVING A CENTRAL TRUNCATEDCONICALLY SHAPED APERTURE FOR SURROUNDING SAID PIPE IN SPACED RELATIONTHERETO AND WITH ITS LARGER DIAMETER NEARER THAT END OF SAID PIPE WHICHIS TO RECEIVE THE FLARE, A SEGMENTAL PIPE-ENGAGING-COLLAR HAVING APLURALITY OF SEPARATE ARCUATE SECTIONS, EACH SECTION HAVING A TAPEREDOUTER SURFACE ENGAGEABLE IN MATING RELATION WITH THE APERTURE IN SAIDYOKE AND HAVING A SERRATED INNER SURFACE ENGAGEABLE WITH A PORTION OFTHE PERIPHERY OF SAID PIPE ADJACENT THE END OF THE PIPE WHICH SERVES ASA SUPPORT FOR SAID ASSEMBLY, AN ABUTMENT MEMBER EXTENDING TRANSVERSELYOF SAID PIPE AND LOCATED SUFFICIENTLY FAR FROM THE END THEREOF TOPROVIDE AN OPEN WORKING SPACE THEREBETWEEN, MEANS RIGIDLY AND ADJUSTABLYCONNECTING SAID ABUTMENT TO SAID YOKE AND COMPLETING THE DETACHABLEASSEMBLY SUPPORTED BY SAID PIPE; A FLARING PLUG HAVING A BASE PORTION, ACYLINDRICAL GUIDE PORTION WITH AN OUTER DIAMETER NO GREATER THAN THEINNER DIAMETER OF THE UNCOMPRESSED LINING OF SAID PIPE, AND A TAPEREDFLARING PORTION CONNECTING SAID BASE AND GUIDE PORTIONS; AND ANEXTENSIBLE PRESSURE-APPLYING MEMBER SEPARATE FROM SAID PLUG AND SAIDABUTMENT AND LOCATED IN SAID OPEN SPACE AND ADAPTED TO PUSH UPON EACH OFSAID ABUTMENT AND SAID BASE PORTION OF SAID PLUG DURING THE FLARINGOPERATION, SAID EXTENSIBLE MEMBER BEING ADAPTED WHEN MOVED IN ANEXTENDING DIRECTION TO FORCE SAID PLUG INTO SAID PIPE AND TO IMPOSETENSION UPON SAID CONNECTING MEANS AND WHEN MOVED IN A CONTRACTINGDIRECTION TO RELIEVE SAID TENSION WHEREBY SAID YOKE, COLLAR, ANDABUTMENT MAY BE REMOVED FROM TEMPORARY SUPPORT UPON SAID PIPE, THUS TOLEAVE SAID PLUG IN PLACE WITHIN SAID PIPE IN ORDER TO MAINTAINCOMPRESSION UPON THE PLASTIC LINING IN THE FLARED END OF SAID PIPE.